The evolution of inflators for automotive inflatable safety systems has resulted in the development of pressurized gas-only inflators, propellant-only inflators, and hybrid inflators. There are of course many design considerations for each of the above-noted types of inflators. In all three systems, two primary design considerations are that the air/safety bag must be expanded a predetermined amount in a predetermined amount of time in order to be operationally effective. As such, substantial development efforts have been directed to how the flow path is established between the inflator and the air/safety bag and how the subsequent flow is provided to the air/safety bag such that the above-identified objectives can be met. In hybrid inflators, which again require both a release of a stored, pressurized gas and an ignition of a gas and/or heat-generating propellant, the manner of establishing the flow path to the air/safety bag and the manner of igniting the propellant must both be addressed in a way which meets the above-noted objectives.
Another increasingly important objective is the manner in which the inflator is assembled. Complex hardware designs commonly require complex assembly procedures which increases the overall cost of the inflator. It is also, of course, important during assembly to not adversely affect the performance characteristics of the inflator and to provide an assembly procedure which is reasonable safe.